Been collecting for 2 weeks now - first thing on the list today once we got setup was to dump the black side. I went to go hook up the black flush and turned on the water, I realized nothing was happening. I have had one these on my other coach so I was expecting to hear water flowing into the Black tank. Nada, zip, zilch on this one.

I curious where the blockage could be? looks like a regular water line that is run from the connection. Wouldn't think it could be kinked but unsure how it routes and terminates into the tank at this time.

This is the install in my GT378 and should be similar to yours. The location of the back flow preventer probably changes per model. As previously stated the GT378's location is in the washer/dryer cabinet provision.

My Wildcat had the flush out valve installed backwards, it had to go back to the dealer who had to cut the piping, reverse the valve & then connect 2 couplers to reattach the pipe. Works great for the last 6 years. If you are still on the warrantee take it back to the dealer.

Maybe the factory worker uncharge of installing the back flow valve does not know there is an arrow? Imagine if you can how many Rv's have the same problem. Mine was fixed in 2010. How many before me & how many after mine was corrected?